U.S. patent number 7,298,335 [Application Number 11/165,909] was granted by the patent office on 2007-11-20 for portable information terminal with communication capabilities.
This patent grant is currently assigned to Lenovo (Singapore) Pte. Ltd.. Invention is credited to Hiroaki Agata, Hideyuki Usui.
United States Patent |
7,298,335 |
Usui , et al. |
November 20, 2007 |
Portable information terminal with communication capabilities
Abstract
A portable information terminal with communication capabilities
according to the present invention comprises a conductive housing,
a display, and a planar antenna. The display is attached to the
inside of the housing. The planar antenna is attached to the
outside of the housing.
Inventors: |
Usui; Hideyuki (Chigasaki,
JP), Agata; Hiroaki (Yokohama, JP) |
Assignee: |
Lenovo (Singapore) Pte. Ltd.
(Singapore, SG)
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Family
ID: |
35505136 |
Appl.
No.: |
11/165,909 |
Filed: |
June 24, 2005 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20050285804 A1 |
Dec 29, 2005 |
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Foreign Application Priority Data
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Jun 24, 2004 [JP] |
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2004-186810 |
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Current U.S.
Class: |
343/702;
343/700MS; 361/679.27 |
Current CPC
Class: |
G06F
1/1616 (20130101); H01Q 9/0421 (20130101); H01Q
1/2258 (20130101); G06F 1/1698 (20130101) |
Current International
Class: |
H01Q
1/24 (20060101); G06F 1/16 (20060101); H01Q
1/38 (20060101) |
Field of
Search: |
;343/702,700MS,830
;361/681 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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08-078931 |
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Mar 1996 |
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JP |
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08-256009 |
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Oct 1996 |
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JP |
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11-355033 |
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Dec 1999 |
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JP |
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2003-283232 |
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Oct 2003 |
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JP |
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Primary Examiner: Chen; Shih-Chao
Attorney, Agent or Firm: Sawyer Law Group LLP
Claims
What is claimed is:
1. A portable information terminal with communication capabilities,
the portable information terminal comprising: an electrically
conductive housing, the electrically conductive housing having a
concave formed over a greater part of a main surface of the
electrically conductive housing; a display attached inside of the
electrically conductive housing; and a planar antenna smaller than
the concave formed over the greater part of the main surface of the
electrically conductive housing, the planar antenna having a
resonator and being installed in the concave of the electrically
conductive housing, wherein the electrically conductive housing
includes a through-hole formed directly underneath the resonator of
the planar antenna so as to not prevent vibration of the
resonator.
2. The portable information terminal according to claim 1, further
comprising a dielectric decorative laminate fitted into the concave
of the electrically conductive housing so as to cover the planar
antenna in the concave of the electrically conductive housing.
3. The portable information terminal according to claim 2, further
comprising a cable connected to the planar antenna and passing
through the through-hole of the electrically conductive
housing.
4. The portable information terminal according to claim 2, wherein
the planar antenna is installed in the concave of the electrically
conductive housing parallel to the display.
5. The portable information terminal according to claim 4, wherein
the planar antenna includes a plurality of WLAN inverted F antennas
operable to carry out diversity transmission and diversity
reception.
6. The portable information terminal according to claim 5, wherein
the planar antenna further includes a Bluetooth inverted F
antenna.
7. The portable information terminal according to claim 6, wherein
the planar antenna is in electric contact with the electrically
conductive housing.
8. The portable information terminal according to claim 7, wherein
the decorative laminate is flat.
9. The portable information terminal according to claim 7, wherein:
the electrically conductive housing is molded of carbon fiber
reinforced plastics, and the planar antenna is in contact with
carbon fibers of the carbon fiber reinforced plastics exposed from
a surface of the electrically conductive housing.
10. The portable information terminal according to claim 1, wherein
the portable information terminal is one of a personal computer, a
personal digital assistant (PDA), of a cellular phone.
11. The portable information terminal according to claim 6, wherein
the planar antenna has a ground portion common to each of the
plurality of WLAN inverted F antennas and the Bluetooth inverted F
antenna.
12. The portable information terminal according to claim 11,
wherein the ground portion of the planar antenna is almost a same
size as a size of the concave of the electrically conductive
housing.
Description
FIELD OF THE INVENTION
The present invention relates generally to a portable information
terminal with communication capabilities, and more specifically, to
a portable information terminal comprising a conductive housing and
a built-in antenna.
BACKGROUND OF THE INVENTION
Some recent notebook type personal computers have a built-in
antenna for a wireless local area network (WLAN) or Bluetooth
(registered trade mark). A planar inverted F antenna (sometimes
called an "F type antenna") suitable for transmitting and receiving
high frequencies is used as this antenna and embedded, for example,
at the top of a rear cover or at the top of both sides of the rear
cover.
Many of today's rear covers are made of a conductive material to
prevent electromagnetic radiation generated within the personal
computers from leaking out. In order to allow an inverted-F antenna
to transmit a radio wave to the outside and receive a radio wave
from the outside, an opening is provided in a rear cover in the
position where the inverted-F antenna is embedded and the opening
is covered with a resin cap.
The antenna requires a ground. However, the conventional structure
as described above does not allow a large ground area to be
provided. Consequently, such conventional antennas have a problem
that they tend to be affected by the conductive material
surrounding the antenna and therefore do not provide stable
transmission and reception.
Accordingly, what is needed is a system and method for overcoming
the above-identified problems. The present invention addresses such
a need.
SUMMARY OF THE INVENTION
A portable information terminal with communication capabilities
according to the present invention comprises a conductive housing,
a display, and a planar antenna. The display is attached to the
inside of the housing. The planar antenna is attached to the
outside of the housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing the external configuration of
a notebook personal computer according to an embodiment of the
present invention;
FIG. 2 is an exploded perspective view showing the configuration of
a rear cover of the notebook personal computer shown in FIG. 1;
FIG. 3 is a partly sectional view of the rear cover and a planar
antenna, which are shown in FIG. 2; and
FIG. 4 is a perspective view showing a structure in which coaxial
cables are attached to the planar antenna shown in FIG. 2.
DETAILED DESCRIPTION
[Description of Symbols]
10 . . . Notebook type personal computer
12 . . . PC main body
16 . . . Rear cover
22 . . . Hinge
24 . . . Concave
26 . . . Planar antenna
28, 30, 32 . . . Inverted F antennas
34 . . . Ground portion
36, 38, 40 . . . Resonators
42, 44, 46 . . . Notches
50, 52, 54 . . . Through-holes
56, 58, 60 . . . Coaxial cables
62 . . . Decorative laminate
The present invention relates generally to a portable information
terminal with communication capabilities, and more specifically, to
a portable information terminal comprising a conductive housing and
a built-in antenna. The following description is presented to
enable one of ordinary skill in the art to make and use the
invention and is provided in the context of a patent application
and its requirements. Various modifications to the preferred
embodiments and the generic principles and features described
herein will be readily apparent to those skilled in the art. Thus,
the present invention is not intended to be limited to the
embodiments shown, but is to be accorded the widest scope
consistent with the principles and features described herein.
An object of the present invention is to provide a portable
information terminal having a built-in antenna capable of providing
stable transmission and reception even if its housing is
electrically conductive.
A portable information terminal with communication capabilities
according to the present invention comprises a conductive housing,
a display, and a planar antenna. The display is attached to the
inside of the housing. The planar antenna is attached to the
outside of the housing. The term "portable information terminal" as
used herein refers to a notebook type personal computer, a PDA
(Personal Digital Assistance), a cellular phone (PHS (Personal
Handyphone System)), or the like. For the notebook type personal
computer, the term "housing" as used herein corresponds to a rear
cover attached to the notebook type personal computer main body so
as to be freely opened and closed.
The portable information terminal employs the conductive housing in
order to block electromagnetic waves generated inside the terminal.
However, since the planar antenna is attached to the outside of the
housing, the terminal is unlikely to be affected by a display
attached to the inside of the housing. As a result, stable
transmissions and receptions can be carried out.
Preferably, the housing has a concave formed over a predetermined
area outside the housing. The planar antenna is attached in the
concave. The portable information terminal further comprises a
dielectric decorative laminate. The decorative laminate is attached
so as to cover the planar antenna.
In this case, the planar antenna is attached in the concave of the
housing and is further covered with the decorative plate.
Accordingly, the planar antenna is formed integrally with the
housing. This simplifies the external configuration of the
terminal. Moreover, the decorative plate is dielectric, so that
radio waves transmitted and received by the planar antenna are not
blocked by the decorative plate.
Moreover, the planar antenna preferably has a resonator. The
housing has a through-hole formed at a position corresponding to
the resonator of the planar antenna. The portable information
terminal further comprises a cable connected to the planar antenna
and passing through the through-hole.
In this case, the through-hole is formed at the position
corresponding to the resonator of the planar antenna. Consequently,
the vibration of the resonator is not prevented. Moreover, the
cable connected to the planar antenna passes through the
through-hole. This simplifies the wiring structure of the
terminal.
Preferably, the planar antenna is in electric contact with the
housing.
In this case, the planar antenna has a larger ground area and can
thus carry out more stable transmissions and receptions.
Moreover, the housing is preferably molded of carbon fiber
reinforced plastics. The planar antenna is in contact with carbon
fibers exposed from a surface of the housing.
In this case, it is possible to ensure that the planar antenna and
the housing are electrically contacted with each other.
An embodiment of the present invention will be described below in
detail with reference to the drawings. The same or corresponding
parts will be denoted by the same reference numerals, and their
descriptions will not be repeated.
With reference to FIG. 1, a notebook type personal computer 10
comprises a main body (hereinafter referred to as a "PC main body")
12, a rear cover 16 attached to the PC main body 12 via hinges 14
so as to be freely opened and closed, and a liquid crystal display
(LCD) 18 attached to the inside of the rear cover 16.
A keyboard 20 and the like are arranged on a top surface of the PC
main body 12. The PC main body 12 contains a printed circuit board
on which a CPU (Central Processing Unit), a memory, and the like
are mounted, a hard disk drive, a flexible disk drive, a CD-ROM
(Compact Disk-Read Only Memory) drive, and the like.
The rear cover 16 is formed of carbon-fiber reinforced plastics
(CFRP) so as not to allow the leakage of electromagnetic waves
generated in the PC main body 12 or the LCD 18.
With reference to FIG. 2, the LCD 18 is installed inside the rear
cover 16 using fixture such as hinges 22. On the other hand, a
rectangular concave 24 is formed over a predetermined area outside
the rear cover 16. The predetermined area occupies the greater part
of, specifically at least half of, preferably 80% of a main surface
of the rear cover 16.
A planar antenna 26 one size smaller than the concave 24 in the
rear cover 16 is installed in the concave 24 parallel to the LCD
18. The planar antenna 26 is formed of metal such as copper,
nickel, a copper-nickel alloy, or phosphor bronze, or their
plating.
The planar antenna 26 has two WLAN inverted F antennas 28 and 30 on
its long side and a Bluetooth inverted F antenna 32 on its short
side. The inverted F antennas 28, 30, and 32 have resonators 36,
38, and 40, respectively, extending from a ground portion 34 like a
key and notches 42, 44, and 46, respectively, formed between the
resonators 36, 38, and 40 and the ground portion 34. The ground
portion 34, which is common to the three inverted F antennas 28,
30, and 32, is sufficiently large compared to the resonators 36,
38, and 40. As shown in the embodiment of FIG. 2, the ground
portion 34 has almost the same size as that of the concave 24.
The planar antenna 26 thus has the WLAN inverted F antennas 28 and
30 and the Bluetooth inverted F antenna 32. Consequently, the
notebook type personal computer 10 can carry out transmissions and
receptions using either system. Moreover, since the planar antenna
26 has the two WLAN inverted F antennas 28 and 30, a diversity
system can be realized.
With reference to FIG. 3, the planar antenna 26 is in electric
surface contact with the rear cover 16. Specifically, as
exaggeratedly shown in FIG. 3, carbon fibers 48, a filler for CFRP,
are exposed from a surface of the rear cover 16. The carbon fibers
48 are in contact with the planar antenna 26 at many points. To
realize such an electric contact, insertion molding is carried out
when the rear cover 16 is formed of CFRP; the planar antenna 26 is
inserted into the CFRP and molded integrally with it.
Alternatively, compression molding may be used to harden CFRP
thermally melted, together with the planar antenna 26.
With reference to FIG. 2 again, in the concave 24 of the rear cover
16, rectangular through-holes 50, 52, and 54 are formed at
positions corresponding to the inverted F antennas 28, 30, and 32
so as not to prevent the vibration of the resonators 36, 38, and
40. As shown in the embodiment of FIG. 2, the rectangular
through-holes 50, 52, and 54 are formed at positions directly
underneath corresponding resonators 36. 38, and 40.
With reference to FIG. 4, a coaxial cable 56 is connected to the
resonator 36 and ground portion 34 of the inverted F antenna 28 by
soldering. The coaxial cable 56 is connected to a transmission and
reception circuit (not shown) in the PC main body 12 through the
through-hole 50 as shown in FIG. 2. Coaxial cables 58 and 60 are
similarly connected to the inverted F antennas 30 and 32,
respectively. The coaxial cables 58 and 60 are connected to the
transmission and reception circuit in the PC main body 12 through
the through-holes 52 and 54.
The coaxial cables 56, 58, and 60 are thus passed through the
through-holes 50, 52, and 54, respectively, formed so as not to
prevent the vibration of the resonators 36, 38, and 40. This
simplifies the wiring structure.
Finally, an adhesive decorative laminate 62 is fitted into and
stuck to the concave 24 of the rear cover 16 so as to cover the
planar antenna 26. In the embodiment shown in FIG. 2, the
decorative laminate is flat. The decorative laminate 62 is a
rectangle having almost the same size as that of the concave 24.
The decorative laminate 62 is formed of a dielectric such as resin.
Accordingly, the planar antenna 26 is formed integrally with the
rear cover 16, thus simplifying the external configuration.
Moreover, radio waves transmitted and received by the planar
antenna 26 are not blocked by the decorative plate 62.
As described above, according to the embodiment of the present
invention, the rear cover 16 is formed of the CFRP in order to
block electromagnetic waves generated in the PC main body 12 or the
LCD 18. However, the planar antenna 26 is attached to the outside
of the rear cover 16 to ensure transmissions and receptions to and
from external equipment. Further, the planar antenna 26 has the
sufficiently large ground portion 34 and is in electric contact
with the conductive rear cover 16. Consequently, the planar antenna
26 is unlikely to be affected by the LCD 18, the hinges 22, or the
like. This enables very stable transmissions and receptions.
Moreover, the planar antenna 26 is attached to the outside of the
rear cover 16. This makes it possible to equally design any forms
of notebook type personal computers.
In the above embodiment, the rear cover 16 is formed of the CFRP.
Alternatively, the rear cover 16 may be formed of a conductive
material such as aluminum or steel. Further, the concave 24, the
planar antenna 26, and the decorative laminate 62 need not be
rectangular but may be square, circular, elliptical, trapezoidal,
or parallelogrammatic. The shapes of these components are not
limited. Furthermore, slot antennas having elongated rectangular
holes may be used in place of the inverted F antennas 28, 30, and
32. The type of the planar antenna is not limited. Moreover, a
plasma display or the like may be used in place of the LCD 18.
The present invention is applicable not only to the notebook type
personal computer but also to a PDA, a cellular phone, and the
like. For a PDA or a cellular phone in which the LCD is integrated
with the main body, the planar antenna may be attached to the
outside of a conductive housing that accommodates the main body and
the LCD. For a PDA or a cellular phone in which the LCD is attached
to the main body so as to be freely opened or closed, the planar
antenna may be attached to the outside of a conductive rear cover
(housing) that accommodates the LCD.
Although the present invention has been described in accordance
with the embodiments shown, one of ordinary skill in the art will
readily recognize that there could be variations to the embodiments
and those variations would be within the spirit and scope of the
present invention. Accordingly, many modifications may be made by
one of ordinary skill in the art without departing from the spirit
and scope of the appended claims.
* * * * *